This is really great stuff. I'm writing a story on this at the Google Earth Blog. I do have a suggestion for improvement: make your network link be nested network links where each subfolder is a network link. That way you only download the currently "clicked-on" subfolder and it will load a lot faster without really creating a lot of work. It will also mean less impact on your server.

I also recommend you save the network link with the selected "amateur satellites" folder open so people can quickly understand what is going on.